L-95-133, Application for Amends to Licenses DPR-67 & NPF-16.Amends Would Allow Up to Seven Days to Restore an Inoperable LPSI Train to Operable Status

Application for Amends to Licenses DPR-67 & NPF-16.Amends Would Allow Up to Seven Days to Restore an Inoperable LPSI Train to Operable Status

ML17309A792
Person / Time
Site:	Saint Lucie
Issue date:	06/21/1995
From:	Sager D FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17228B182	List: L-95-133, Application for Amends to Licenses DPR-67 & NPF-16.Amends Would Allow Up to Seven Days to Restore an Inoperable LPSI Train to Operable Status ML17228B181 ML17228B183
References
L-95-133, NUDOCS 9506230233
Download: ML17309A792 (16)

Text

REORIA'ZY 1 (ACCELERATED RIDS PROCESSING) 0 NOTES:

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9506230233 DOC.DATE: 95/06/21 NOTARIZED: YES DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power

& Light Co.

05000335 P 50-389 St. Lucie Plant, Unit 2, Florida Power

& Light Co.

05000389 AUTH.NAME AUTHOR AFFILIATION SAGER,D.A.

Florida Power

& Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

~5 I

SUBJECT:

Application for amends to licenses DPR-67

& NPF-16.Amends would allow up to seven days to restore an inoperable LPSI train to operable status.

DISTRIBUTION CODE:

AOOID COPIES RECEIVED:LTR 1

ENCL

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SIZE:

I 2+5 5 TITLE: OR Submittal:

General Distribution RECIPIENT ID CODE/NAME PD2-1 LA NORRIS,J INTERNAL: ACRS NRR/DE/EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT EXTERNAL: NOAC COPIES LTTR ENCL 1

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NOTE TO ALL "RIDS" RECIPIENTS-PLEASE HELP US TO REDUCE WASTE!

CONTACT THE DOCUMENT CONTROL

DESK, ROOM OWFN 5DS (415-2083)

TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED'OTAL NUMBER OF COPIES REQUIRED:

LTTR 18 ENCL 17

Florida Power 5 Light Company, P.O. Box 128, Fort Pierce, FL 34S54-0128

%PL June 21, 1995 L-95-133 10 CFR 50.90 U.

S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.

C.

20555 RE:

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension Pursuant to 10 CFR 50.90, Florida Power

& Light Company (FPL) requests to amend Facility Operating Licenses DPR-67 and NPF-16 for St.

Lucie Unit 1 and Unit 2, respectively, by incorporating the attached Technical Specifications.

(TS) revisions.

The proposed amendments will revise TS 3.5.2 to allow up to 7 days to restore an inoperable Low Pressure Safety Injection train to operable status.

This proposal is a result of a cooperative study by participating Combustion Engineering Owners Group members which concluded that an extension of the allowed outage time (AOT) from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days can improve plant operational flexibilityand is risk beneficial.

It is requested that the proposed amendments, if approved, be issued by February 29, 1996.

Attachment 1 is an evaluation of-the proposed changes.

Attachment 2 is the "Determination of No Significant Hazards Consideration."

Attachments 3

and 4 contai'n copies of the appropriate technical specifications pages marked up to show the proposed changes.

Enclosed with this submittal is a

copy of CE-NPSD-995, "Joint Applications Report for Low Pressure Safety Injection System AOT Extension,"

May, 1995.

The proposed amendments have been reviewed by the St.

Lucie Facility Review Group and the FPL Company Nuclear Review Board.

In accordance with 10 CFR 50.91 (b)

(1),

copies of the proposed amendments are being forwarded to the State Designee for the State of Florida.

Please contact us if there are any questions about this submittal.

Very truly yours, D. A.

er Vice P e ident St. Luc'e Plant

/

9506230233 95062i PDR ADQCK 05000335 PDR an FPL Group company I

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St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Page 2

DAS/RLD Attachments Enclosure CGA Stewart D. Ebneter, Regional Administrator, Region II, USNRC.

Senior Resident Inspector, USNRC, St. Lucie Plant.

Mr. W.A. Passetti, Florida Department of Health and Rehabilitative Services.

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Page 3

STATE OF FLORIDA

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COUNTY OF ST.

LUCIE

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D. A. Sager being first duly sworn, deposes and says:

That he is Vice President, St. Lucie Plant for the Nuclear Division of Florida Power 6 Light Company, the Licensee herein; That he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information and belief, and that he is authorized to execute the document on behalf of said Licensee.

D. A.

S er STATE OF FLORIDA COUNTY OF 5TL WA The foregoing instrument was acknowledged before me this ~l day of 19 $5 by D.A. Sager, who is personally known to me and who did take an oath.

KAKEN Name of Notary Public My Commission expires Commission No. '5 KAREN WEST

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St. Lucie Unit 1 and Unit 2

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Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension ATTACHMENT 1 EVALUATXON OF PROPOSED TS CHANGES 0.

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St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 1

Page 1 of 4 EVALUATION OF PROPOSED TS CHANGES Introduction Florida Power and Light Company (FPL) requests that Appendix A of Facility Operating License DPR-67 for St. Lucie Unit 1 (PSL1) and NPF-16 for St. Lucie Unit 2 (PSL2) be revised to extend the action completion/allowed outage time (AOT) for an inoperable Low Pressure Safety Injection (LPSI) train from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days.

The purpose of the AOT extension is to enhance overall plant safety by avoiding potential unscheduled plant shutdowns, and by providing for increased flexibilityin scheduling and performing maintenance and surveillance activities.

The proposed AOT extension is based on the results of a

cooperative study performed by participating members of the Combustion Engineering Owners Group (CEOG).

The study included an integrated review and assessment of plant operations, deterministic design basis factors, and overall plant risk using Probability Safety Assessment (PSA) techniques.

Descri tion of PSL1 and PSL2 Pro osed TS Chan es The following proposed changes apply to both PSL1 and PSL2:

TS 3.5.2 ACTION a. will be revised by adding the following footnote:

Ifthe ECCS subsystem is inoperable only because the LPSI train is inoperable, the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit may be extended to a maximum of 7 days from initialdiscovery offailure to meet the LCO."

I'eflect the proper system nomenclature.

Marked-up copies of the affected TS pages are contained in Attachment 3

(PSL1) and Attachment 4

(PSL2).

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 1

Page 2 of 4 Back round The Emergency Core Cooling System (ECCS) includes two independent and redundant subsystems, each consisting of a

LPSI train in combination with a High Pressure Safety Injection (HPSI) train.

As demonstrated in the plant specific safety analyses for PSL1 and PSL2, either one of the ECCS subsystems operating in conjunction with the Safety Injection Tanks (SIT) willsatisfy the requisite 10 CFR 50.46 ECCS acceptance criteria.

Each LPSI train contains a high volume, low head; centrifugal pump designed to supplement the Safety Injection Tank (SIT) inventory in re-flooding the reactor vessel with borated water during the early stages of a large break Loss of Coolant Accident (LOCA).

The LPSI system is actuated by an automatic or manually initiated Safety Injection Actuation Signal (SIAS), which starts the associated pump and causes the LPSI flow control valves to open.

The LPSI pumps transfer borated water from the Refueling Water Tank (RWT), through the LPSI header(s),

and into the safety injection penetrations for the Reactor Coolant System (RCS) cold legs.

During the recirculation phase of the LOCA scenario, the LPSI pumps are stopped by an automatic or manually initiated Recirculation Actuation Signal (RAS).

The LPSI systems for both St. Lucie units are functionally the

same, but contain differences in the piping arrangement, e.g.,

PSL1 has a common LPSI header which branches out to each of the four high pressure cold leg penetrations whereas PSL2 has two independent LPSI headers, each branching out to two of the high pressure cold leg penetrations.

The LPSI systems are also used for decay heat removal during normal shutdown cooling operations in MODES 4, 5, and 6.

In the shutdown cooling configuration, the LPSI pumps circulate reactor coolant from the RCS hot legs, through Shutdown Cooling Heat Exchangers (SDHX), and into the RCS cold leg penetrations.

Limiting Condition for Operation (LCO) 3.5.2 requires two independent ECCS subsystems to be OPERABLE in MODES 1 and 2, and in MODE 3 when RCS pressure is ~ 1750 psia.

This redundancy provides assurance that sufficient emergency core cooling capability willbe available in the event of a

LOCA, assuming the loss of one subsystem through any single-failure consideration.

In the event one of the ECCS subsystems becomes inoperable, LCO 3.5.2 requires that subsystem to be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 1

Page 3 of 4 the plant must transition to MODE 4 (Hot Shutdown) within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> AOT prescribed by LCO 3.5.2 is based on an NRC study, circa

1975, "using a reliability evaluation

[of ECCS components]

and is a reasonable amount of time to effect many repairs."

(Ref:

NUREG-1432, Standard Technical Specifications for Combustion Engineering Plants, Rev.

0; 9/28/92)

Bases for the Pro osed Chan es FPL participated in a

CEOG effort to perform an

. integrated assessment of the impact of extending the AOT for an inoperable LPSI train from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days.

The assessment considered the impact of the AOT extension on deterministic factors associated with applicable plant design

bases, and a probabilistic safety assessment of risks involved with applicable plant operations.

The considerations, assumptions, methodologies, and detailed results of this study are reported in CE NPSD-995, "Joint Applications Report for Low Pressure Safety Injection System AOT Extension,"

Final Report CEOG Task 836, prepared for the CE Owners Group, May, 1995, which is enclosed with this submittal.

Plant specific calculations to assess the risk impact of the AOT extension on PSL1 and PSL2 were performed by FPL using current PSA models and methods that were initially developed in response to Generic Letter 88-20, "Individual Plant Examination for Severe Accident Vulnerabilities."

CE NPSD-995 contains the results of FPL's plant specific

analyses, as well as generic information relevant to the proposed AOT extension that is applicable to both St.

Lucie Units.

The enclosed

report, therefore, forms the justification/basis for the proposed license amendments.

The analyses for PSL1 and PSL2 indicate that.

continued plant operation with a single LPSI train out of service will result in a small increase in "at power risk;<< however, when the full scope of plant risk is considered, the risk incurred by extending the AOT for the performance of maintenance activities would be offset by risk benefits associated with averting unnecessary plant transitions to Hot Shutdown and/or by reducing risk during shutdown operations.

In addition, the proposed AOT extension for the LPSI system is evaluated as having a negligible impact on the large early radiological release probability for CE Pressurized Water Reactors in the event of a design basis accident.

The evaluation

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 1

Page 4 of 4 reported in CE NPSD-995 concludes that the net impact of the proposed amendment would be risk beneficial.

Conclusion The risk contributions associated with extending the AOT for a

single inoperable LPSI train from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days have been quantitatively evaluated using the current plant specific Probabilistic Safety Assessment for PSL1 and PSL2.

The analyses show that the small increase in the calculated "at power risk" can be offset by averting the risk associated with an unnecessary plant transition to Hot Shutdown, and/or reduced risk during shutdown operations that can result from improved flexibilityin scheduling and performing surveillance and maintenance activities.

The integrated assessment reported in CE NPSD-995 generally conforms to guidance provided in NUREG/CR-6141, "Handbook of Methods for Risk Based Analyses of Technical Specifications,"

December, 1994.

Relative to the average Core Damage Frequency calculated for the appropriate severe accidents, NUREG/CR-6141

states, "A risk-based AOT assures that the single event and yearly AOT risk contributions are acceptable."

FPL believes the proposed 7 day AOT qualifies as a beneficial risk-based AOT( and that the proposed amendment is acceptable.

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension ATTACHMENT 2.

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 2

Page 1 of 2 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION Pursuant to 10CFR50.92, a determination may be made that a proposed license amendment involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:

(1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a

new or different kind of accident from any accident previously evaluated; or (3) involve a

significant reduction in a margin of safety.

Each standard is discussed as follows:

(1)

Operation of the facility in accordance with the proposed amendment would not involve a

significant increase in the probability or consequences of an accident previously evaluated.

The proposed amendments for St. Lucie Unit 1 and Unit 2 will extend the action completion/allowed outage time (AOT) for a

single inoperable Low Pressure Safety Injection (LPSI) train from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days.

A LPSI train is designed as a part of each Emergency Core Cooling System (ECCS) subsystem to supplement Safety Injection Tank (SIT) inventory during the early stages of mitigating a Design Basis Accident.

As such, components of the LPSI system are not accident initiators, and an extended AOT to restore operability of an inoperable LPSI train would not increase the probability of occurrence of accidents previously analyzed.

The safety analyses for both St. Lucie Units demonstrate that ECCS performance acceptance criteria are satisfied with only one of the two redundant ECCS subsystems operating during the postulated Design Basis Accident.

The proposed technical specification revisions involve the AOT for a single inoperable LPSI train, and do

not, change the conditions assumed for the minimum amount of operating equipment needed for accident mitigation.

Therefore, the consequences of an accident previously evaluated will not be significantly increased.

In addition to the preceding evaluation, a Probabilistic Safety Analysis (PSA) was performed to quantitatively assess the risk impact of the proposed amendments.

It was concluded from the results of that assessment that the risk contribution of the AOT

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension L-95-133 Attachment 2

Page 2 of 2 extension is very small, and that the net impact of the proposed amendment can be risk beneficial.

Therefore, operation of either facility in accordance with its proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

(2)

Operation of the facility in accordance with the proposed amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed amendments will not change the physical plant or the modes of plant operation defined in either Facility License.

The changes do not involve the addition or modification of equipment nor do they alter the design of plant systems.

Therefore, operation of either facility in accordance with its proposed amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.

(3)

Operation of the facility in accordance with the proposed amendment would not involve a significant reduction in a margin of safety.

The margin of safety associated with the ECCS system is established by acceptance criteria for system performance defined in 10 CFR 50.46.

The proposed amendments will not change this acceptance criteria nor the operability requirements for equipment that is used to achieve such performance as demonstrated in the plant safety analyses.

Moreover, an integrated assessment of the risk impact of extending the AOT for a single inoperable LPSI train has concluded that the risk contribution is very small, LPSI system reliability can potentially be improved, and the net impact of the proposed change can be risk beneficial.

Therefore, operation of either facility in accordance with its proposed amendment would not involve a significant reduction in a margin of safety.

Based on the above discussion and the supporting Evaluation of Technical Specification

changes, FPL has determined that the proposed license amendments involve no significant hazards consideration.

St. Lucie Unit 1 and Unit 2 Docket Nos.

50-335 and 50-389 Proposed License Amendments LPSI S stem AOT Extension ATTACHMENT 3 ST ~ LUCIE UNIT 1 MARKED-UP TECHNICAL SPECIFICATION PAGES Page 3/4 5-3 Page 3/4 5-5